Do you happen to know what the specification on the transistor may be? I've searched that code and got no results. I've found lots of 6pin Mosfet Transistors on Farnell but have know Idea which may be compatable.

Hi,
I tried to find some specification on the Internet, too - nothing...

There is one Fet for each disk and 5V and 12V Power supply.
.
On my board I made a simple test and connected a resistor instead of the disk.
Then I measured how much the voltage drops at the transistor.